rubber vine mgt guide

8/8/2019 Rubber Vine Mgt Guide

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The problem

Rubber vine is a Weed of National

Significance. It is regarded as one of the

worst weeds in Australia because of its

invasiveness, potential for spread, and

economic and environmental impacts.

Rubber vine has impacts on pastoral

and conservation areas of northeastern

Australia. Its main impact on pastoralism

is the loss of grazing country, which

in 1995 was estimated to cost the

Queensland beef industry $18 million.

It also increases the costs of mustering

and fencing.

Rubber vine threatens waterways,

woodlands and rainforests throughout

northeastern Australia, including

significant conservation areas such as

the Wet Tropics World Heritage Area

and Cape York. It also severely threatens

riverine vegetation, and can potentially

displace the plants and animals that

inhabit riverbanks, thereby affecting

the water quality of streams. The whole

ecological integrity of native vine thickets

and riverine systems of northern Australia

is under threat from rubber vine.

The weed

Rubber vine is a many stemmed shrub

which can climb 30 m into t ree canopies,

or grow 13 m high when unsupported

in open areas. The stems are greyish

brown with a smooth bark and have two

forms: a leaf-bearing branched stem and

a longer unbranched whip with fewer

leaves that extends onto nearby adjacent

vegetation. The plant exudes a milky

sap if scratched or broken.

The leaves occur in pairs and are a glossy

dark green in colour. They are oval-shaped

with tapered ends (elliptical), 60100 mm

long and 3050 mm wide. The trumpet-

shaped flowers are quite large, up to

50 mm long and wide, with five light

purple to white petals.

The seed pods are rigid and usually occur

in opposing pairs at the end of short

stalks, but are quite common as single

pods and occasionally triple pods. The

pods are up to 120 mm long and 40 mm

wide. The brown seeds are flat with

a tuft of long, white, silky hairs at one

end. Roots grow to a depth of 12 m.

Key points

Rubber vine threatens to choke the

waterways, vine forests and pastures of

northern Australia.

Its westward spread must be prevented to

protect environmental and economic interests

in the Northern Territory and northern Western

Australia.

A containment line helps to prioritise infestations

for control and to monitor progress.

Existing control techniques (chemical, mechanical,

biological and fire) should be integrated for

maximum effect.

Follow-up work needs to be ongoing, especially

if seeds re-enter the site.

w e e d s o f n a t i o n a l s i g n i f i c a n c e

R u b b e r v i n e C r y p t o s t e g i a g r a n d i f l o r a

q Current q Potential

RubbervineCryptoste

giagrandiflora

Rubber vine smothers and kil ls native vegetation. It is a severe threat to biodiversity in northern Australia:

Burdekin River, Qld.

Photo: Colin G. Wilson

Rubber vine (Cryptostegia grandiflora)


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How it spreads

About 95% of seed produced by

rubber vine is viable. It is scattered short

distances from the parent plant by wind

that catches the tufts on the seed ends,

or longer distances by floating on

floodwaters. Most seed remains viable

even after the pods have floated on fresh

or salt water for over a month, potentially

leading to spread between catchments.

Seeds can also be potentially spread by

birds, or in mud attached to vehicles,machinery and animals.

With each seed pod producing between

340 and 840 seeds, a hectare of rubber

vine can produce millions of seeds every

year. However, the seed is not long

lived. If conditions are too dry to allow

germination, most of the seed will die

after one year.

Rubber vine was first planted in the

gardens of mining towns of northern

Queensland in the late 1860s. Weedy

infestations were reported by 1917.

During the Second World War rubber

vine was cultivated as a potential source

of rubber, contributing to its spread.

In 1991 the total area of rubber vineinfestation was estimated at over

700,000 ha of tropical and subtropical

Queensland, although it was present

over an area 50 times as large. Two

infestations, since controlled, were also

found in northern Western Australia in

the 1990s.

Where it grows

Rubber vine typically invades new areas

when seed is blown in or transported

down a waterway. Seed germinates

readily on riverbanks and other moist

areas, and the young plants rapidly grow

over and smother other plants, often

completely dominating the vegetation.

It then spreads aggressively from the

riverbank to adjoining open woodland

and/or pastures.

Currently, rubber vine is restricted to areasreceiving between 400 and 1400 mm

of mainly summer rain. It grows on all

soil types, but is more likely to germinate

on soils that retain moisture.

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W e e d M a n a g e m e n t G u i d e R u b b e r v i n e C r y p t o s t e g i a g r a n d i f l o r a

Each seed pod can produce over 800 seeds, which are spread short distances when the tufts are

blown by the wind.


90mm

Rubber vine mainly flowers during summer:

Charters Towers, Qld, in December.Photo: Colin G. Wilson

Growth calendar

Rubber vine seedlings do not flower until the diameter of the stem at its base is at

least 15 mm. Under normal conditions in Queensland this occurs shortly after the

first year of growth. Although rubber vine can flower at almost any time of the year,

most f lowering takes place in summer. Seed pod formation usually occurs from

summer to late autumn. Seed pods are not generally formed until the stem diameter

has reached 35 mm at its base. The pods dry out and are ripe after about 200 days,

when they split open and release the seeds.

Germination occurs following good rain. Seeds need between 5 and 15 days exposure

to moist, warm (2030C) conditions before they will germinate. Wet, shaded areas

that protect the seeds from drying out are therefore ideal for rubber vine.

Rubber vine plants are thought to live for up to 80 years.

FloweringPod formation

Seed drop

Germination

Dormancy

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

General growth pattern Growth pattern under suitable conditions

35 mm


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Rubber vine is native to southwestern

Madagascar. It has become weedy in

other countries throughout East Africa,

South-East Asia, the United States, and

Central and South America.

Potential distribution

Based on its climatic requirements,

rubber vine has a potential distribution

covering all of northern Queensland and

northern Northern Territory, and most

of the Kimberley and Pilbara regions of

Western Australia. Parts of northeastern

New South Wales could also be affected.

What to do about it

Prevention of spread outside

the Rubber Vine Containment

Line

Prevention is the cheapest form of

controlling rubber vine. The Rubber Vine

Containment Line was surveyed in the

early 1990s to highlight areas infested

with the weed and help plan control

efforts. Strategies inside the containment

line are focused on managing its impact.

Any infestations outside the containment

line are targeted for control to prevent

its spread into new areas.

Other ways to prevent the spread of

rubber vine include:

preventing its sale and planting by

declaring it a weed across all states

and territories

preventing further importation

raising public awareness of the

problems.

How to control rubber vine

Early efforts to control rubber vine have

improved our understanding of control

techniques and how to combine, or

integrate, different methods to give the

best results. There are four main methods

that are used to control the weed:

biological, chemical, fire and mechanical.

The longer unbranched whip extends out of the top of vines. It has few leaves but is used to climb

onto other vegetation.

Photo: Joe Vitelli, Qld DNRM

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RubbervineCryptoste

giagrandiflora

A strategic plan for integrated management of rubbervine

The Queensland Department of Natural Resources and Mines and the National

Rubber Vine Management Group have developed the Rubber Vine Management

Manual Control and Case Studies, with funding contributed by the National Weeds

Program of the Natural Heritage Trust. It contains the five-step approach to planning

which is summarised below.

Accurate mapping of all infestations is an ideal starting point that will provide

the information required to identify infestations as priorities for control.

Control attempts should aim to kill plants before they set seed, first targeting

outlying or small infestations and working towards the centre. Because wind and

water are the main ways in which seed is spread, priorit ise inf estat ions that arelikely to be a source of seeds (eg in upper catchments, or upwind in relation to

prevailing winds). Infestations that have severe impacts on property maintenance

(eg watering or mustering points) or primary production might also be high

priorities for control.

Choosing appropriate control methods is a key part of the strategic plan.

Aiming for maximum effect with minimum cost, it is important to first evaluate what

resources (eg labour, herbicides, spray equipment, machinery) are available. Part of

this evaluation will be assessing the different costs of each control method and of

each of the identified priorities, and developing a financial plan for both the

short and long terms.

Finally, it is important to target contro l effort s to suitable times of the year to

take advantage of differences between seasons or any abnormal fluctuations (such

as drought or flooding). For example, good rains generate pasture growth, which

can be used to fuel fires.


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Biological control reduces

rubber vines vigour

Two biological control agents have

become widespread in Queensland since

their release in the early 1990s. The rubber

vine rust Maravalia cryptostegiaeforms

on the underside of leaves and causes

them to turn yellow and drop. The rust

thrives during the wet season but is less

active over the dry season. Frequent

showers early in the season should

result in heavy infestations of rust.

The other agent is the moth Euclasta

whalleyi, whose caterpillars feed on rubber

vine leaves between March and October.

The moth has a black spot on each wing

and characteristically rests with its wings

folded at 45 to a vertical surface. The

caterpillars tend to feed on the underside

of new leaves, often leaving fine silken

threads and black bead-like droppings.

Both agents, especially the rust, cause

damage (eg reduced flowering, seed pod

production and leaf cover) and occasion-

ally the death of established plants.

However, their effectiveness varies with

climatic conditions.

Herbicides are effective but

expensive

The strategic use of a range of registered

herbicides is an effective method of

controlling isolated or outlying rubber

vine plants. Foliar spraying the entire

plant f rom the ground and aerial spraying

are most effective on smaller plants

(less than 2 m tall, stem diameter less

than 35 mm). However, note that leaves

infected by the biocontrol rust will not

take up herbicides. The basal bark

technique, which uses spraying around

the lowest bark up to a height of 500 mm

(knee height), is effective on plants of

stem diameter less than 35 mm at the

base. For thicker rubber vine, up to 90 mm

stem diameter at base, basal bark spray

to 1 m high. Foliar, aerial and basal bark

spraying should only be conducted when

rubber vine is actively growing.

When the stem diameter at the base

exceeds 90 mm, or if the stems are heavilyintertwined, the cut-stump method is

preferred. The stems should be cut as

close to the ground as possible using a

machete or chainsaw, and immediately

painted with herbicide. The cut-stump

method uses minimal herbicides and is

effective at all times but is labour intensive

and therefore best suited to scattered

infestations.

Soil-applied residual herbicides are

effective when applied before rain. Soil

type limits their effectiveness, and there

are other important considerations such

as run-off and impacts on non-target

trees. It is highly recommended that

advice is obtained f rom the relevant

state/territory weed management agency

prior to the use of soil-applied herbicides.

Fire is relatively inexpensive

and kills rubber vine

Fire is an especially valuable part of the

integrated control of rubber vine because

it kills surface seeds, seedlings and adult

plants, yet is relatively inexpensive. If there

is sufficient fuel, rubber vine can be

burnt whilst green with good success.Infestations may require an initial burn

to open them out, a follow-up burn to

control regrowth and seedlings in the

next 12 months, and another burn several

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g Larvae of the biological control agent Euclasta whalleyifeeding on rubber vine leaves, ChartersTowers, June.

Photo: Rachel McFadyen

Adult Euclasta whalleyiare active at night, and

are recognisable by a black spot on the wing

and their habit of resting with their wings at

an angle of 45 to a vertical surface.


15mm

20

mm


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Weed control contacts

State /

Territory

NSW

NT

Qld

WA

Australia wide

Department

NSW Agriculture

Dept of Infrastructure,Planning and Environment

Dept of Natural Resources

and Mines

Dept of Agriculture

Australian Pesticides and

Veterinary Medicines Authority

Phone

1800 680 244

(08) 8999 5511

(07) 3896 3111

(08) 9368 3333

(02) 6272 5852

Email

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

Website

www.agric.nsw.gov.au

www.nt.gov.au

www.nrm.qld.gov.au

www.agric.wa.gov.au

www.apvma.gov.au

years later to continue the follow-up.

In a fire research experiment west of

Chillagoe in Queensland, 80% of rubber

vine was killed in an initial fire (October

1997). A follow-up burn one year later

resulted in a 99% kill rate.

The timing of fire is crucial to its success

as fires must be hot enough to kill mature

rubber vine. The fuel load should be about

1500 kg/ha, the equivalent of a relatively

thin pasture. Pasture may need to be

fenced off, or spelled, before burning

to allow it to build to high enough levels.

These costs, and the construction of fire

breaks, make up the bulk of the costs

associated with fire.

Fire combined w ith biocontrol

provides cost-eff ect ive cont rol of

rubber vine.

It is advisable to burn after first rains as

this reduces the risk of prolonged periods

of bare earth and erosion. Other factors

that must be considered when using

fire include its impacts on pastures and

natural ecosystems, risks to stock and

property, and loss of nutrients. Permits

may be required to light fires check

with your local council or state or territory

weed management agency.

Mechanical control helps

gain accessBlade or disc ploughs and cutter bars

provide reasonable control of rubber

vine, but are most often used to

penetrate very dense infestations to

allow easier access or to open up the

canopy. Slashing harms the plant but

often does not kill it.

5


RubbervineCryptoste

giagrandiflora

For up-to-date information on which herbicides are registered to control rubber vine and the best application methods and dosages, contact your state or territory

weed management agency or local council. This information varies from state to state and from time to time. Contact details are listed above, including contacts

for the Australian Pesticides and Veterinary Medicines Authority, which hosts the PUBCRIS database. This database contains information on all herbicides that are

registered for use on weeds in each Australian state and territory.

When using herbicides, always read the l abel and f ollow instructions carefull y. Particular care should be taken when using herbicides near wat erways

because rainfall running off the land into waterways can carry herbicides with it. Permits from state or territory Environment Protection Authorities

may be required i f herbicides are to be sprayed on ri ver banks.

With sufficient fuel (grasses, rubber vine leaves,

other vegetation), f ire can successfully control

rubber vine. Fire is especially efficient in

combination with rubber vine rust.


1m

Mechanical control is mainly used to open up infestations and allow better access to rubber vine

for herbicide application or to help provide fuel for fires.



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Mechanical control is not suited to core

problem areas such as gullies and creeks

because it can lead to erosion. Also, care

must be taken not to inadvertently bury

plant material (eg seeds, stems) thatcould be protected from a fire. Permits

may be required to conduct mechanical

control if native species will be affected.

Weed control contacts (see table p. 5)

will be able to provide relevant advice.

Chemical, mechanical and biological

control, fire and grazing management

can be integrated together to manage

rubber vine in the long term.

Integrated management is

most effective

Recent research has shown that the use

of fire after biological control can be

highly effective. The biocontrol rust causes

leaf drop, which opens up infestations

and allows grasses to grow underneath.Combined with the rubber vine leaf

litter, these grasses can provide the

perfect environment for fires, resulting

in excellent, cost-effective control.

However, there is no single method of

integrating techniques that is suitable for

all infestations; control programs should

be tailored to the location, size, intensity

and age of each situation. Other factorsthat must also be considered are the

effects on other vegetation and the

availability of resources for control and

follow-up operations. Landholders should

contact their local weeds officer or lands

protection off icer for the most

appropriate strategy.

Controlling rubber vine is hard work

and requires ongoing commitment. The

benefits of controlling it include: recovered

pasture, increased production, reduced

mustering costs and the protection of

natural ecosystems, plants and animals.

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The seed pods normally form between December and April, and occur in pairs at the end of stems.


180mm

Another weedy species ofCryptostegia

Cryptostegia madagascariensisis closely related to rubber vine, and also occurs either

in gardens or as a naturalised weed in Western Australia, the Northern Territory

and Queensland. Its flowers are slightly smaller and a deeper pink colour but it is

otherwise diff icult to separate the two species. The risks posed by Cryptostegia

madagascariensisare high, especially because it could cross-breed with rubber vine.

Note that the common name rubber vine may also be used for other unrelated

nursery plants.

Cryptostegia madagascariensisis similar in

appearance to rubber vine, and poses similar

threats as it escapes from gardens.


25mm


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case study

Holmleigh Station is a cattle property

south of Prairie in the uplands of Tower

Creek in northern Queensland. John andBub Teakle run about 600 head on the

15,600 ha station, which forms part of

the very upper Lake Eyre Basin.

The Teakles did not take much notice

of the rubber vine when they first took

over the station in 1989. The extent of

the problem was revealed in 1992 when

the Strategic Weed Eradication and

Education Program (SWEEP) helped to

map the infestation, and found that it

followed Tower Creek through Holmleigh

and adjoining stations for about 9 km.

According to John Teakle, one of the

main problems with rubber vine is that

the catt le get hidden in it when

mustering once they know its there

the cattle will look for it . Although both

biocontrol agents are present, it is too

dry for the rust and the moth is prone

to parasitism.

In the Tower Creek area SWEEP provided

an initial control effort aimed at knocking

out the bulk of the rubber vine stands.

The SWEEP team used foliar applied

herbicides, but could not get access to

some very dense infestations. Although

they made some progress, upstream

plants continually reinfested treated

areas, and the ongoing follow-up that

was required was beyond the resources

of most of the landholders.

Since that initial control attempt, John

Teakle has used fire to gain better access

and help thin out dense infestations.

Fire is the first thing anyone should

doBurn any time you can get a fire

to burn and it s safe to burn , he says.

It is crucial that the fires are intense

enough to burn up through the green

rubber vine and kill it. Fire is a relatively

inexpensive method of control and can

help to reduce the amount of seed

produced.

With funding secured through the

Natural Heritage Trust, the Teakles have

employed contractors to help with

chemical control of rubber vine, using

the cut-stump technique for plants over

30 mm diameter and basal bark spraying

for anything smaller.

The Teakles are not seeking major

economic gains from rubber vine control

as it does not spread into their pastures.

They mainly see the benefits in clearing

their property and protecting the

downstream Channel Country.

RubbervineCryptoste

giagrandiflora

Legislation

Landholders throughout Western Australia,

the Northern Territory and Queensland

are required by law to control both speciesof Cryptostegiathat occur on their land.

Check with your local council or state/

territory government agency about its

requirements for rubber vine control.

Acknowledgments

Information and guide revision: Darren

Moor (Qld DNRM) and members of the

Rubber Vine Management Group,including Mark Bickhoff, Phil Maher

(Qld DNRM), Leslee Marshall, Noel Wilson

(Dept of Agriculture WA/Weeds CRC)

and Tony Grice (CSIRO/Weeds CRC).

Other assistance from Rachel McFadyen

(Weeds CRC), Sandy Lloyd (Dept of

Agriculture WA/Weeds CRC), John and

Bub Teakle (Holmleigh Station), Michele

Deveze (Qld DNRM) and John Thorp

(National Weeds Management Facilitator).

Maps: Australian Weeds Committee.

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Rubber vine infestation in Qld, where the total area of infestation was estimated at 700,000 ha in

1991. Its total range extends across some 35 million ha, or 20% of the state.


Protecting the Channel Country...case study


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Prevent spread outside the

containment line

All infestations outside the Rubber Vine

Containment Line should be controlled

to prevent further spread. Monitoring

and early detection are required to targetthese infestations. Communication and

education are critical to achieving early

detection in new areas.

Integrated managementwithin the containment line

Infestations within the Rubber Vine

Containment Line should be managed

to minimise impacts and reduce the

amount of seed produced. Integratedcontrol using a mix of fire, biological,

mechanical and chemical methods is

the most cost-effective long-term

approach.

The five step approach toplanning

Use the five step planning approach, as

devised by the Queensland Department

of Natural Resources and Mines and the

National Rubber Vine Management Group:

1. Map infestations on your property.

2. Target sites that are sources of seed

spread, strategically important or

essential for property management.

3. Determine the availability of resources

(eg herbicides, labour) and suitability

of methods for dif ferent infestations

(eg herbicides are too expensive for

very dense or large infestations, f ire

is especially effective after rust infection).

4. Estimate the cost of the program and

incorporate into the short- and long-

term property budget.

5. Calendar control efforts for maximum

results and minimum effort. For

example, wait until an adequate fuel

load exists before using fire.

Ongoing follow-up

Follow-up control must be diligent and

ongoing, as rubber vine can quickly

reinfest.

Q u i c k r e f e r e n c e g u i d e

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Disclaimer

While every care is taken to ensure the accuracy of the information in this publication, the CRC for Australian Weed Management and the Commonwealth Department of the Environmentand Heritage take no responsibility for its contents, nor for any loss, damage or consequence for any person or body relying on the information, or any error or omission in this publication.

2003 Information w hich appears in this guide may be reproduced wit hout w ritten permission provided the source of the inf ormation is acknowledged.Printed in Australia on 100% recycled paper.

ISBN 1-920932-15-1

Type of infestation

Light (less than 1000

plants per ha)

Medium (10002000

plants per ha)

Heavy (more than

2000 plants per ha)

Fire

Moderately hot fires

using grass as a fuel will

give good kill rates.

Hotter fires are required

to ignit e and kill rubber

vine in denser

infestations. Either

exclude stock to build

up fuel, or burn after

rust has defoliated

rubber vine. Ideally, burn

in late spring or after

rain to avoid bare earth

and erosion.

Mechanical

Slashing kills only about

50% of rubber vine.

Consider other methods.

Cutter bar gives best

control. Do not use on

steep slopes.

Blade ploughing can kill

most rubber vine, but is

mainly used to open up

infestations and allow

better access. Do not

use on steep slopes.

Chemical

Foliar or basal bark spray, or use

cut-stump method with registered

herbicide when actively growing.

Foliar or aerial spray, or apply

registered herbicide to soil when

actively growing.

Aerial spray or apply registered

herbicide to soil. Note it is very

expensive to control large

infestations with herbicides, and

foliar sprayed herbicides are less

effective on rubber vine infected

with rust.

Biological

Two biological agents are

having an impact in

reducing the health andspread of rubber vine

the rubber vine rust and

the rubber vine moth.

An additional benefit

of the rust is that it opens

up the canopy to allow

flammable undergrowth

to grow. However,

biocontrol agents will only

rarely kill mature rubber

vine plants on their own.

Control options

The rubber vine rust Maravalia cryptostegiae

appears as yellow blotches on the underside of

the leaves. It thrives in the wet season, particularly

after steady early rains.


60 mm

rubber vine mgt guide

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